package Demo5;

import java.util.PriorityQueue;
import java.util.TimerTask;

class MyTimerTask implements Comparable<MyTimerTask>{

    private Runnable task;
    private long time;

    public MyTimerTask(Runnable task, long time) {
        this.task = task;
        this.time = time;
    }

    public long getTime() {
        return time;
    }

    public void run(){
        task.run();
    }
    @Override
    public int compareTo(MyTimerTask o) {
        return (int)(this.time-o.time);
    }
}

class MyTimer{
    private PriorityQueue<MyTimerTask> queue=new PriorityQueue<>();
    private Object locker=new Object();

    public void schedule(Runnable task,long delay){
        synchronized (locker){
            MyTimerTask timerTask=new MyTimerTask(task,System.currentTimeMillis()+delay);
            queue.offer(timerTask);
locker.notify();
        }
    }

    public MyTimer(){
        Thread t=new Thread(()->{
                    try {
                        while(true){
                            synchronized (locker){
                           while(queue.isEmpty()){
                                    locker.wait();
                                }
                           MyTimerTask task=queue.peek();
                            if(System.currentTimeMillis()< task.getTime()){
                                locker.wait(task.getTime()-System.currentTimeMillis());
                            }else {
                                task.run();
                                queue.poll();
                            }
                }
            }
                    }
                    catch (InterruptedException e) {
                        throw new RuntimeException(e);
        }
        });
        t.start();
    }
}




public class Main16 {
    public static void main(String[] args) {
        MyTimer timer=new MyTimer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("hello 3000");
            }
        }, 3000);

        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("hello 2000");
            }
        }, 2000);

        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("hello 1000");
            }
        }, 1000);
        System.out.println("hello main");
    }
}
